This invention relates to a semiconductor device and a method of manufacturing the semiconductor device, particularly to the semiconductor device having an improved packaging structure of IC (Integrated Circuit), LSI (Large Scale Integration), and the like, which have terminals and conductive wires arranged in narrow pitch fashion, and the method of manufacturing such a semiconductor device.
Conventionally, a method using shrinkage power of a heat-hardened resin has been employed to connect a plurality of projective electrodes of a semiconductor element after sealing with conductive wires on a substrate. An example of the method is exemplified, as a prior art, in Japanese Patent Publication No. Hei 6-105727, namely, 105727/1994. As will later be described more in detail, a semiconductor device fabricated by the use of the conventional method has a structure in which hardenning and shrinking power of an insulative resin is larger than a thermal stress of the insulative resin at a desirable temperature.
However, the shrinking power of the insulative resin for fixing the semiconductor element to the substrate is generated uniformly over a connected area between the semiconductor element and the substrate. The shrinking power of the insulative resin is larger at a high temperature than at an ordinary temperature. A difference of the shrinking power therebetween is generated, as a thermal stress, repeatedly on the insulative resin every time heat is generated and disappeared by the semiconductor device in use. The thermal stress makes the insulative resin fatigued and accelerates a deterioration thereof so that the shrinkage power of the insulative resin is decreased. As a result, a quantity of expansion of the insulative resin comes to exceed a quantity of shrinkage thereof. Consequently, voids are generated between a projective electrode of the semiconductor element and a conductive wire of the substrate. Accordingly, a defective conduction is inevitably caused to occur between the projective electrode and the conductive wire.